The U.S. Environmental Protection Agency (EPA) has found levels in filters in 12 of their radiation-monitoring stations “slightly higher” than those found by EPA monitors last week and a Department of Energy monitor the week before. But they are “still far below levels of public health concern,” the agency states.

EPA’s samples were captured by monitors in Alaska, Alabama, California, Guam, Hawaii, Idaho, Nevada,
Saipan, Northern Mariana Islands and Washington state. Two tables present air sampling data for eight radionuclides, showing “trace amounts of radioactive isotopes consistent with the Japanese nuclear incident”: Barium-140 (Ba-140), Cobalt-60 (Co-60), Cesium-134 (Cs-134), Cesium-137 (Cs-137), Iodine-131 (I-131), Iodine-132 (I-132), Iodine-133 (I-133), and Tellurium-132 (Te-132). The results show the sampling location and the average concentration of radionuclides in picocuries per cubic meter (pCi/m3) over the sampling period.

On Monday night, Japanese authorities confirmed that they had identified plutonium in soil samples around the Fukushima Daiichi nuclear plant.